Dual High Efficiency Charge Pump
for White LED and Flash Applications
Electrical Characteristics
1
V
IN
= 3.6V; C
IN
= C
OUT
= C
1
= C
2
= C
3
= 1.0µF; T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are T
A
= 25°C.
Symbol
V
IN
AAT2805
Description
Operation Range
Conditions
Min Typ Max Units
2.7
5.5
1
3.0
3.0
µA
4.5
1.0
10
0.5
4.32
4.3
120
250
100
1.0
0.4
1.4
0.3
50
75
500
500
-1.0
1.0
75
7
4.5
4.5
4.68
4.7
V
mA
µA
%
%
Ω
V
Input Power Supply
I
CC
Operating Current
I
SHDN
I
DX
I
(D-Match)
R
SINK
V
OUT_FL
I
OUT_FL
T
SS
F
CLK
V
EN(L)
V
EN(H)
T
EN/SET LO
T
EN/SET_HI_MIN
T
EN/SET_HI_MAX
T
OFF
T
LAT
I
I
Shutdown Current
Input Current Accuracy
2, 3
Current Matching Between
VD1:D4 = 3.6, V
IN
= 3.5V
Any Two Current Sink Inputs
2, 4
Sink Switch Impedance (each)
2
3.0V < V
IN
< 5V, I
OUT
= 100mA;
Flash Charge Pump Output
EN_FLSH = V
IN
5
3.0V < V
IN
< 5V, I
OUT
= 150mA;
Voltage
EN_FLSH = V
IN
5
Maximum Continuous I
OUT
V
IN
= 3.6V; V
OUT
= 4.5V; EN_FLSH = V
IN
5
Maximum Pulsed I
OUT
V
IN
= 3.6V; V
OUT
= 4.5V; I
PULSED
< 500ms
Soft-Start Time
Clock Frequency
Enable Threshold Low
Enable Threshold High
EN/SET Low Time
V
EN/SET
< 0.6V
Minimum EN/SET High Time
V
EN/SET
> 1.4V
Maximum EN/SET High Time
EN/SET Off Timeout
6
V
EN/SET
< 0.6V
7
EN/SET Latch Timeout
V
EN/SET
> 1.4V
Enable and EN/SET Input
V
EN/SET
= V
EN_FLSH
= V
IN
Leakage
1X Mode, 3.0
≤
V
IN
≤
5.5, Active, No Load
Current; EN_FLSH = GND, EN/SET = V
IN
1.5X Mode, 3.0
≤
V
IN
≤
5.5, Active, No Load
Current; EN_FLSH = GND, EN/SET = V
IN
2X Mode, 3.0
≤
V
IN
≤
5.5, Active, No Load
Current; EN_FLSH = GND, EN/SET = V
IN
EN_FLSH = GND, 50µA Output Setting,
1X Mode
3.0
≤
V
IN
≤
5.5, No Load Current;
EN_FLSH = V
IN
, EN/SET = GND
EN_FLSH = EN/SET = 0
I
SET
= 30mA; T
A
= 25°C
0.3
1.0
1.0
50
2.0
mA
-10
mA
µs
MHz
V
V
µs
ns
µs
µs
µs
µA
1. The AAT2805 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by
design, characterization, and correlation with statistical process controls.
2. Specification applies only to the tri-mode charge pump.
3. Determined by the average of all active channels.
4. Current matching is defined as the deviation of any sink current from the average of all active channels.
5. Specification applies only to the charge pump doubler.
6. The EN/SET pin must remain logic low (less than V
EN(L)
) for the duration of longer than 500µs to guarantee the off timeout.
7. The EN/SET pin must remain logic high (greater than V
EN(H)
) for the duration of longer than 500µs to guarantee the latch timeout.
4
2805.2006.04.1.7
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
